HT46F46E/HT46F47E/HT46F48E/HT46F49E
A/D Transfer Function
transfer function between the analog input value and the
digitised output value for the A/D converters.
As the HT46F46E device contain an 8-bit A/D converter,
their full-scale converted digitized value is equal to
0FFH. Since the full-scale analog input value is equal to
the voltage, this gives a single bit analog input value of
Note that to reduce the quantisation error, a 0.5 LSB off-
set is added to the A/D Converter input. Except for the
digitised zero value, the subsequent digitised values will
change at a point 0.5 LSB below where they would
change without the offset, and the last full scale digitised
value will change at a point 1.5 LSB below the VDD level.
V
DD/256. For the other devices which each contain a
9-bit A/D converter, their full-scale converted digitised
value is equal to 1FFH giving a single bit analog input
value of VDD/512. The following graphs show the ideal
1
.
5
L
S
B
F
F
H
F
E
H
F
D
H
A
R
/
D
C
o
n
v
e
r
s
i
o
n
e
s
u
l
t
0
.
5
L
S
B
0
0
0
3
2
1
H
H
H
V
D
D
(
)
2
5
6
6
0
1
2
3
2
5
2
3
5
4
2
5
5
2
5
A
n
a
l
o
g
I
n
p
u
t
V
o
l
t
a
g
e
Ideal A/D Transfer Function - HT46F46E
1
.
5
L
S
B
1
F
F
H
1
F
E
H
1
F
D
H
A
R
/
D
C
o
n
v
e
r
s
i
o
n
e
s
u
l
t
0
.
5
L
S
B
0
0
0
3
2
1
H
H
H
V
D
D
(
)
5
1
2
2
0
1
2
3
5
0
5
9
1
0
5
1
1
5
1
A
n
a
l
o
g
I
n
p
u
t
V
o
l
t
a
g
e
Ideal A/D Transfer Function - Other Devices
Rev. 1.40
44
July 28, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
